Ulnar Gutter Splint Application Procedure

An ulnar gutter splint extends from the proximal forearm to distal interphalangeal joints of fingers on the ulnar aspect of fingers wrist and forearm and is applied for various injuries of the ulnar aspect of the wrist and hand.

It is also called Boxer splint.

The splint is applied on the ulnar aspect and conforms to the ulnar aspect part (the part of the limb on side of pinky finger ) of the arm, wrist, hand, and fingers.

The wrist is slightly extended and the injured fingers are flexed forward in a rounded position.

The splint includes only pinky and adjoining fingers and other digits of the hand are not included. The

Splints are used to provide support and comfort through stabilization of an injured part. The splints can be used as a definitive treatment or serve as a temporary measure until definitive treatment is done.

Splints can also be used in the postoperative period to provide desired immobilization.

[More on Splints]

[More on types of splints]

Indications of Ulnar Gutter Splint

The splint is applied for ulnar injuries of wrist, hand and lower forearm. These include

• Soft tissue injury of the fourth and fifth fingers
• Fractures of fourth and fifth metacarpal
• Fractures of the phalanges of fourth and fifth fingers

The ulnar gutter splint can also be used in positioning for rheumatoid arthritis or osteoarthritis

The procedure of  Ulnar Gutter Splint Application

Items required

Equipment employed in ulnar gutter splinting includes the following (see the image below):

• Stockinette
• Padding/cotton
• Bandage or wrap
• Clean, room-temperature water in a basin
• Tape or bandage clips

Anesthesia

Often, the simple splinting does not need anesthesia/analgesia but with reductions involved anesthesia may be used.

Hematoma block,  nerve block, sedation, analgesia [NSAIDs, opoid]. Combination of sedation.

Patient Position

The patient may be seated or reclined or supine. A sedated patient should not be in sitting position.

The patient is covered in a drape to avoid splatter from the wet plaster.

Expose the injured limb and remove all the jewelry. Any jewelry like bangle or ring can cause constriction and edema.

Stockinette Application

After explaining the whole procedure to the patient [with risks involved],  apply the stockinette.

The distal end of the stockinette is cut to allow coverage of the fourth and fifth digits and leaving other fingers. An adequate hole for the thumb is made.

The stockinette should extend 2-3 cm beyond the overlying padding on either end which in turn is 2-3 cm beyond the overlying wet plaster extent.

Later both will be pulled over the edges of the wet plaster to create smooth edges.

Padding Application

To prevent skin maceration,   place a piece of padding between the fourth and fifth digits. Now wrap the padding [commercially available or made from cotton] from one end to other. The usual thumb rule is to overlap the previous layer by at least half the width. Some authors suggest two-thirds overlapping.

Padding should be smooth, without wrinkles and snug to the limb without constricting effects or being too tight. Extend 2-3 cm beyond the overlying intended plaster on both ends.

Bony prominence should be padded extra. [the wrist, the metacarpophalangeal joints, and the interphalangeal joints]

In cases where moderate-to-significant swelling is anticipated, the padding is cut lengthwise along the lateral or radial side of the forearm before applying the wet plaster. This allows for expansion of the padding due to swelling.

Plaster Splint Preparation

Measure the plaster. Use a plaster bandage that is 4 inches in breadth [comes in sizes of 3, 4, 5 6 inches]. The breadth can be changed according to forearm girth.

Measure the plaster from the fifth distal IP joint to the proximal third of the forearm. Allow for roughly 5 mm of extra length on either end for shrinkage of wet plaster in the setting process.

Create a 12-14 layered splint of the desired length by folding over the plaster bandage and stacking the folds to create the splint.

Excess wet plaster on the ends will be folded over.

[The steps above are usually skipped in prefabricated fiberglass bandages.  In this case, the manufacturer’s recommendations need to be followed.]

Application of Splint

Hold the created splints from both ends and dip in clean, room-temperature water. Allow all the bubbles to escape. This starts the lamination process of the plaster and allows the layers to bond together.

Squeeze out the excess water

Now, put the plaster on a flat surface or dry towel and smooth out wrinkles and folds. This allows increases bonding of the plaster layers.

Apply the wet plaster, over the padding, to the medial or ulnar surface of the forearm. Fold the excess plaster outward on the ends.

An assistant would now hold the slab while wrapping bandages are applied

Fold stockinette and padding to the extent of the plaster to create smooth edges.

[I personally find it to be easier  after a single layer of the wrap is applied]

The wrapping starts distally, at the distal interphalangeal joints of the fourth and fifth digits, and wrap proximally.

Avoid wrapping too tightly.

Position and mold the plaster while it is still wet. Bring wrist in 20° extension and metacarpophalangeal joint in flexion of 70° [imagine the patient holding a glass in his hand].

Use broad-based pressure to mold the plaster. The plaster is typically molded by using the palmar surface of the and not fingertips. Fingertip pressure may cause denting in plaster and thus pressure points leading to sores.

Keep the hand, wrist, and forearm immobile until the splint is dry.

The patient would feel some warmth released from the plaster as it dries. In case of intense heat [very rare]  unwrap the splint and remove the plaster immediately as thermal burns can occur. It usually occurs when the water used is too warm or not clean.

Check for neurovascular function and capillary refill after the splint has been applied. Clean the excess plaster that may have dropped onto the patient’s skin.

The following video would aid in understanding the procedure

After Splint Care

[Read more on plaster care]

The patient is instructed to rest and elevate the limb.

The patient should report back immediately in the emergency department if there is increased weakness or numbness or color change (pale or blue). Same should be done in cases of pain that does not relent, feeling of plaster constriction.

A spreading redness or streaking should be reported immediately too.

Plaster should be kept dry and clean.

The patient should not stick any items into the splint to scratch an itch. Sticking objects into the splint can wrinkle the padding and lead to pressure sores. It may also cause a break of skin and infection that would be overlooked because of the presence of covers.

Call the patient back for a recheck after 48 hours and further as necessary.

Complications of Ulnar Gutter Splint

[Read more on complications of plaster]

• Skin burns form plaster heat during setting
  • may occur when very hot water is used]
  • Wrapping towels or blankets around the splint after application to shorten drying time may cause excess heat.
• Pressure sores
  • provide extra padding  at  prominences
  • Avoid creases.
• Contact dermatitis
  • Antihistmines provide relief
• Swelling and pain
  • Remove splint and elevate the limb
  • Reapply after swelling is gone.
• Joint stiffness
  • Noticed after splint removal
  • requires physical therapy.

References

• Howes DS, Kaufman JJ. Plaster splints: techniques and indications. Am Fam Physician. 1984 Sep. 30(3):215-21.
• Gulabi D, Avci CC, Cecen GS, Bekler HI, Saglam F, Merih E. A comparison of the functional and radiological results of Paris plaster cast and ulnar gutter splint in the conservative treatment of fractures of the fifth metacarpal. Eur J Orthop Surg Traumatol. 2014 Oct. 24(7):1167-73.